There is often a need to track the location of anatomical structures during a surgical procedure. For example, in spinal surgery, the abundance of sensitive body tissues around the spine demands extreme precision to ensure that paralysis, and even death, is avoided. Surgical navigation systems are often used for such surgeries to provide approximate locations of vertebral levels and spinal segments to the surgeon, e.g., during insertion of pedicle or lateral mass screws. A typical surgical navigation system registers and tracks each vertebral level individually relative to both the patient and other vertebral levels by affixing navigation markers to each vertebra.
Existing surgical navigation systems can have numerous shortcomings. Instrumenting each individual vertebra with a navigation marker can further clutter an already limited surgical space and increase the complexity, cost, and processing requirements of the navigation system. Individual vertebrae can also shift or rotate relative to each other during the surgery, requiring frequent re-registration to ensure that the proper reference frame is maintained. Placing navigation markers on each vertebra can also be overly invasive and increase surgeon fatigue, as well as time spent in the operating room.
Accordingly, there is a continual need for systems and methods that improve registration and tracking of anatomical structures during surgical procedures.